From c3eda23b450fd1e9c9f86928d8b1991a2dffc4e1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Gr=C3=A9goire=20Henry?= <gregoire.henry@tezos.com>
Date: Mon, 16 Apr 2018 00:44:24 +0200
Subject: [PATCH] Shell: add a global watcher for new valid blocks in `State`

---
 src/lib_shell/state.ml  | 10 ++++++++--
 src/lib_shell/state.mli |  2 ++
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/src/lib_shell/state.ml b/src/lib_shell/state.ml
index 818747d04..50ac27296 100644
--- a/src/lib_shell/state.ml
+++ b/src/lib_shell/state.ml
@@ -24,6 +24,7 @@ type global_state = {
   global_data: global_data Shared.t ;
   protocol_store: Store.Protocol.store Shared.t ;
   main_chain: Chain_id.t ;
+  block_watcher: block Lwt_watcher.input ;
 }
 
 and global_data = {
@@ -588,6 +589,7 @@ module Block = struct
         end >>= fun () ->
         let block = { chain_state ; hash ; contents } in
         Lwt_watcher.notify chain_state.block_watcher block ;
+        Lwt_watcher.notify chain_state.global_state.block_watcher block ;
         return (Some block)
       end
     end
@@ -607,8 +609,8 @@ module Block = struct
         return true
     end
 
-  let watcher chain_state =
-    Lwt_watcher.create_stream chain_state.block_watcher
+  let watcher (state : chain_state) =
+    Lwt_watcher.create_stream state.block_watcher
 
   let operation_hashes { chain_state ; hash ; contents } i =
     if i < 0 || contents.header.shell.validation_passes <= i then
@@ -687,6 +689,9 @@ module Block = struct
 
 end
 
+let watcher (state : global_state) =
+  Lwt_watcher.create_stream state.block_watcher
+
 let read_block { global_data } ?pred hash =
   Shared.use global_data begin fun { chains } ->
     Chain_id.Table.fold
@@ -833,6 +838,7 @@ let read
     global_data = Shared.create global_data ;
     protocol_store = Shared.create @@ Store.Protocol.get global_store ;
     main_chain ;
+    block_watcher = Lwt_watcher.create_input () ;
   } in
   Chain.read_all state >>=? fun () ->
   may_create_chain state main_chain genesis >>= fun main_chain_state ->
diff --git a/src/lib_shell/state.mli b/src/lib_shell/state.mli
index a419d20a8..b9450a544 100644
--- a/src/lib_shell/state.mli
+++ b/src/lib_shell/state.mli
@@ -156,6 +156,8 @@ val read_block:
 val read_block_exn:
   global_state -> ?pred:int -> Block_hash.t -> Block.t Lwt.t
 
+val watcher: t -> Block.t Lwt_stream.t * Lwt_watcher.stopper
+
 val compute_locator: Chain.t -> ?size:int -> Block.t -> Block_locator.seed -> Block_locator.t Lwt.t
 
 val fork_testchain: